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<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="geometry.reference.core.closure"></a><a class="link" href="closure.html" title="closure">closure</a>
</h4></div></div></div>
<p>
          <a class="indexterm" name="idm45246426440912"></a>
Metafunction defining <span class="bold"><strong>value</strong></span> as the closure
          (clockwise, counterclockwise) of the specified geometry type.
        </p>
<h6>
<a name="geometry.reference.core.closure.h0"></a>
          <span class="phrase"><a name="geometry.reference.core.closure.synopsis"></a></span><a class="link" href="closure.html#geometry.reference.core.closure.synopsis">Synopsis</a>
        </h6>
<p>
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">closure</span>
<span class="special">{</span>
  <span class="comment">// ...</span>
<span class="special">};</span>
</pre>
<p>
        </p>
<h6>
<a name="geometry.reference.core.closure.h1"></a>
          <span class="phrase"><a name="geometry.reference.core.closure.template_parameter_s_"></a></span><a class="link" href="closure.html#geometry.reference.core.closure.template_parameter_s_">Template
          parameter(s)</a>
        </h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                  <p>
                    Parameter
                  </p>
                </th>
<th>
                  <p>
                    Description
                  </p>
                </th>
</tr></thead>
<tbody><tr>
<td>
                  <p>
                    typename Geometry
                  </p>
                </td>
<td>
                  <p>
                    Any type fulfilling a Geometry Concept
                  </p>
                </td>
</tr></tbody>
</table></div>
<h6>
<a name="geometry.reference.core.closure.h2"></a>
          <span class="phrase"><a name="geometry.reference.core.closure.header"></a></span><a class="link" href="closure.html#geometry.reference.core.closure.header">Header</a>
        </h6>
<p>
          Either
        </p>
<p>
          <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
        </p>
<p>
          Or
        </p>
<p>
          <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">closure</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
        </p>
<div class="note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top"><p>
            The closure is defined for any geometry type, but only has a real meaning
            for areal geometry types (ring, polygon, multi_polygon)
          </p></td></tr>
</table></div>
<h6>
<a name="geometry.reference.core.closure.h3"></a>
          <span class="phrase"><a name="geometry.reference.core.closure.complexity"></a></span><a class="link" href="closure.html#geometry.reference.core.closure.complexity">Complexity</a>
        </h6>
<p>
          Compile time
        </p>
<h6>
<a name="geometry.reference.core.closure.h4"></a>
          <span class="phrase"><a name="geometry.reference.core.closure.example"></a></span><a class="link" href="closure.html#geometry.reference.core.closure.example">Example</a>
        </h6>
<p>
          Examine if a polygon is defined as "should be closed"
        </p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>

<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;</span> <span class="identifier">point_type</span><span class="special">;</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">polygon</span><span class="special">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">polygon_type</span><span class="special">;</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">closure_selector</span> <span class="identifier">clos</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">closure</span><span class="special">&lt;</span><span class="identifier">polygon_type</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">;</span>

    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"closure: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">clos</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span>
        <span class="special">&lt;&lt;</span> <span class="string">"(open = "</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">open</span>
        <span class="special">&lt;&lt;</span> <span class="string">", closed = "</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">closed</span>
        <span class="special">&lt;&lt;</span> <span class="string">") "</span><span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>

    <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
        </p>
<p>
          Output:
        </p>
<pre class="programlisting">closure: 1
(open = 0, closed = 1)
</pre>
<h6>
<a name="geometry.reference.core.closure.h5"></a>
          <span class="phrase"><a name="geometry.reference.core.closure.see_also"></a></span><a class="link" href="closure.html#geometry.reference.core.closure.see_also">See
          also</a>
        </h6>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
              <a class="link" href="../enumerations/closure_selector.html" title="closure_selector">The
              closure_selector enumeration</a>
            </li></ul></div>
</div>
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      Bruno Lalande, Mateusz Loskot, Adam Wulkiewicz, Oracle and/or its affiliates<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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